Skip to content

Course home

Sign up

2 Statistics

EasyMediumHard
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324
Question 46

The value of a particular model of car, £V\pounds V£V, when it is t t\,t years old is modelled by

V=abtV = ab^{t}V=abt

where a a\,a and b b\,b are constants.

A dealer records the value of a number of these cars of different ages. The data are coded using y=log⁡10Vy = \log_{10} Vy=log10​V, and the regression line of y y\,y on t t\,t is found to be

y=4.28−0.0862ty = 4.28 - 0.0862ty=4.28−0.0862t

a.

Express V V\,V in the form Ae−ktAe^{-kt}Ae−kt, where A A\,A and k k\,k are positive constants. Give the values of A A\,A and k k\,k to 3 significant figures.

[4]
b.

Using this model, find how long it takes for the value of one of these cars to fall to one third of its value when new. Give your answer to the nearest month.

[3]
Markscheme

2 Statistics Questions

  1. A Level
  2. /Maths
  3. /2 Statistics

Question bank